Somatostatin

Full name: SRIF / GH-inhibiting hormone

A 14-amino-acid (and 28-AA extended form) cyclic peptide produced in the hypothalamus, pancreas, and gastrointestinal tract. Inhibits GH, TSH, insulin, glucagon, and gastrin secretion. Acts as the natural brake on pituitary GH release, counterbalancing GHRH. Clinically mimicked by octreotide and lanreotide for treating acromegaly and endocrine tumors.